Greubel Forsey GMT White Gold

Launched in 2011, the GMT White gold model by Greubel Forsey features a number of complications and functions such as: 2nd time zone GMT display, Tourbillon 24 Secondes, rotating globe with universal time display, 24 time zone world-time display, summer time indicator, world-time disc with summer time zones, day-and-night indicator, power-reserve indicator, hour and minute display, small second indicator, GMT pusher and lastly the equatorial sapphire crystal lateral window.
This grand complication model is equipped with a mechanical hand-wound movement, Calibre GF05 that is made of 436 parts. Greubel Forsey GMT model comes in 43.50 mm white gold case featuring asymmetrical convex sapphire crystal and three-dimensional, variable geometry-shaped lugs.

Technical details
Functions
2nd time zone GMT display
Tourbillon 24 Secondes
Rotating globe with universal time display
24 time zone world time display
Summer time indicator
World time disc with summer time zones
Day-and-night indicator
Power-reserve indicator
Hour and minute display
Small second indicator
GMT pusher
Equatorial sapphire crystal lateral window

Movement
Mechanical hand-wound movement, Calibre GF05
2 patents pending, Movement with patented tourbillon
Diameter: 36.40 mm, Thickness: 12.46 mm

Number of parts
Complete movement: 436 parts, Tourbillon cage: 87 parts
– Weight of the cage: 0.36 g
– Number of jewels: 50, Olived-domed jewels in gold chatons

Power reserve: 72 hours
Barrels: Two coaxial series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
Balance wheel: Free sprung variable-inertia balance with gold meantime screws (10 mm diameter)
Frequency: 21’600 vibrations/hour
Balance spring: Phillips terminal curve, Geneva-style stud
Main Plates: Nickel silver, frosted and spotted with polished beveling and countersinks, straight-grained flanks, nickel palladium-finish

Bridges
• Nickel silver, frosted and spotted, nickel-palladium finish, hand-bevelled, straight-grained flanks, polished countersinks
• Gold nameplates bearing the individual number of the timepiece
• Flat black polished steel tourbillon bridge, hand-bevelled

Gearing
• Involute circle profile
• Conical gearing with corrected profiles

Tourbillon cage
• Inclined at a 25° angle, 24-second rotation
• Cage pillars in Avional
• Titanium cage bridges
• Gold counterweight

Displays
Hour and minute
Small second
72-hour power reserve on a sector
2nd time zone GMT indicator
24 time zone worldtime display
Rotating globe with universal time display
Summer time indicator
Day-and-night indicator

Case
White gold with asymmetrical convex sapphire crystal
Transparent back with asymmetrical convex sapphire crystal
Three-dimensional, variable geometry-shaped lugs
Polished bezel and centre band with hand-finished straight graining
Lateral window with shaped sapphire crystal
White gold pusher with raised polished engraving “GMT“ on a hand-punched background
Raised polished engraving “Greubel Forsey” on a hand-punched background
Hand-engraved individual number
Gold security screws
Case dimensions: Diameter: 43.50 mm, Thickness: 16.14 mm
Water resistance of the case: 3 atm – 30 m – 100 ft (standard NIHS 92-20/SN ISO 22810:2010)
Crown: In white gold with engraved and black lacquered GF logo

Dial
Principal hour-minute dial in gold, frosted, anthracite finish (NAC).
Hour indicator: white gold, circular graining.
Gold power reserve sector, matt lapped
Gold small second indicator, matt lapped
Gold GMT indicator, matt lapped
Applied gold Greubel Forsey logo

Hands
Hour and minute in polished gold, with Super- Luminova
Small second and power-reserve in blued steel
2nd time zone GMT indicator, red triangle

Strap and clasp
Hand-sewn blue or black alligator
White gold folding clasp, hand-engraved with the Greubel Forsey logo

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